mus: Get the gpu memory buffer from the window server.

services/ui/public/cpp/mojo_gpu_memory_buffer_manager.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/public/cpp/mojo_gpu_memory_buffer_manager.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/shared_memory.h"
+#include "base/synchronization/waitable_event.h"
 #include "gpu/ipc/client/gpu_memory_buffer_impl.h"
 #include "mojo/public/cpp/system/buffer.h"
 #include "mojo/public/cpp/system/platform_handle.h"
+#include "services/service_manager/public/cpp/connector.h"
 #include "ui/gfx/buffer_format_util.h"
 
 namespace ui {
 
-MojoGpuMemoryBufferManager::MojoGpuMemoryBufferManager()
-    : weak_ptr_factory_(this) {}
+namespace {
 
-MojoGpuMemoryBufferManager::~MojoGpuMemoryBufferManager() {}
+void OnGpuMemoryBufferAllocated(gfx::GpuMemoryBufferHandle* ret_handle,
+                                base::WaitableEvent* wait,
+                                const gfx::GpuMemoryBufferHandle& handle) {
+  *ret_handle = handle;
+  wait->Signal();
+}
+
+}  // namespace
+
+MojoGpuMemoryBufferManager::MojoGpuMemoryBufferManager(
+    service_manager::Connector* connector)
+    : thread_("GpuMemoryThread"),
+      connector_(connector->Clone()),
+      weak_ptr_factory_(this) {
+  CHECK(thread_.Start());
+  // The thread is owned by this object. Which means the test will not run if
+  // the object has been destroyed. So Unretained() is safe.
+  thread_.task_runner()->PostTask(
+      FROM_HERE, base::Bind(&MojoGpuMemoryBufferManager::InitThread,
+                            base::Unretained(this)));
+}
+
+MojoGpuMemoryBufferManager::~MojoGpuMemoryBufferManager() {
+  thread_.task_runner()->PostTask(
+      FROM_HERE, base::Bind(&MojoGpuMemoryBufferManager::TearDownThread,
+                            base::Unretained(this)));
+  thread_.Stop();
+}
+
+void MojoGpuMemoryBufferManager::InitThread() {
+  connector_->ConnectToInterface("service:ui", &gpu_service_);
+}
+
+void MojoGpuMemoryBufferManager::TearDownThread() {
+  gpu_service_.reset();
+}
+
+void MojoGpuMemoryBufferManager::AllocateGpuMemoryBufferOnThread(
+    const gfx::Size& size,
+    gfx::BufferFormat format,
+    gfx::BufferUsage usage,
+    gfx::GpuMemoryBufferHandle* handle,
+    base::WaitableEvent* wait) {
+  DCHECK(thread_.task_runner()->BelongsToCurrentThread());
+  // |handle| and |wait| are both on the stack, and will be alive until |wait|
+  // is signaled. So it is safe for OnGpuMemoryBufferAllocated() to operate on
+  // these.
+  gpu_service_->CreateGpuMemoryBuffer(
+      gfx::GpuMemoryBufferId(++counter_), size, format, usage,
+      base::Bind(&OnGpuMemoryBufferAllocated, handle, wait));
+}
 
 void MojoGpuMemoryBufferManager::DeletedGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     const gpu::SyncToken& sync_token) {
+  if (!thread_.task_runner()->BelongsToCurrentThread()) {
+    thread_.task_runner()->PostTask(
+        FROM_HERE,
+        base::Bind(&MojoGpuMemoryBufferManager::DeletedGpuMemoryBuffer,
+                   base::Unretained(this), id, sync_token));
+    return;
+  }
+  gpu_service_->DestroyGpuMemoryBuffer(id, sync_token);
 }
 
 std::unique_ptr<gfx::GpuMemoryBuffer>
 MojoGpuMemoryBufferManager::AllocateGpuMemoryBuffer(
     const gfx::Size& size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
     gpu::SurfaceHandle surface_handle) {
-  // TODO(sad): Get the memory buffer handle from GpuService.
-  size_t bytes = gfx::BufferSizeForBufferFormat(size, format);
-
-  mojo::ScopedSharedBufferHandle handle =
-      mojo::SharedBufferHandle::Create(bytes);
-  if (!handle.is_valid())
+  // Note: this can be called from multiple threads at the same time. Some of
+  // those threads may not have a TaskRunner set.
+  DCHECK_EQ(gpu::kNullSurfaceHandle, surface_handle);
+  CHECK(!thread_.task_runner()->BelongsToCurrentThread());
+  gfx::GpuMemoryBufferHandle gmb_handle;
+  base::WaitableEvent wait(base::WaitableEvent::ResetPolicy::AUTOMATIC,
+                           base::WaitableEvent::InitialState::NOT_SIGNALED);
+  thread_.task_runner()->PostTask(
+      FROM_HERE,
+      base::Bind(&MojoGpuMemoryBufferManager::AllocateGpuMemoryBufferOnThread,
+                 base::Unretained(this), size, format, usage, &gmb_handle,
+                 &wait));
+  wait.Wait();
+  if (gmb_handle.is_null())
     return nullptr;
-
-  base::SharedMemoryHandle shm_handle;
-  size_t shared_memory_size;
-  bool readonly;
-  MojoResult result = mojo::UnwrapSharedMemoryHandle(
-      std::move(handle), &shm_handle, &shared_memory_size, &readonly);
-  if (result != MOJO_RESULT_OK)
-    return nullptr;
-  DCHECK_EQ(shared_memory_size, bytes);
-
-  const int stride = base::checked_cast<int>(
-      gfx::RowSizeForBufferFormat(size.width(), format, 0));
-
-  gfx::GpuMemoryBufferHandle gmb_handle;
-  gmb_handle.type = gfx::SHARED_MEMORY_BUFFER;
-  gmb_handle.id = gfx::GpuMemoryBufferId(++counter_);
-  gmb_handle.handle = shm_handle;
-  gmb_handle.offset = 0;
-  gmb_handle.stride = stride;
-
   std::unique_ptr<gpu::GpuMemoryBufferImpl> buffer(
       gpu::GpuMemoryBufferImpl::CreateFromHandle(
           gmb_handle, size, format, usage,
           base::Bind(&MojoGpuMemoryBufferManager::DeletedGpuMemoryBuffer,
                      weak_ptr_factory_.GetWeakPtr(), gmb_handle.id)));
-  if (!buffer)
+  if (!buffer) {
+    DeletedGpuMemoryBuffer(gmb_handle.id, gpu::SyncToken());
     return nullptr;
-
+  }
   return std::move(buffer);
 }
 
 std::unique_ptr<gfx::GpuMemoryBuffer>
 MojoGpuMemoryBufferManager::CreateGpuMemoryBufferFromHandle(
     const gfx::GpuMemoryBufferHandle& handle,
     const gfx::Size& size,
     gfx::BufferFormat format) {
   NOTIMPLEMENTED();
   return nullptr;
 }
 
 gfx::GpuMemoryBuffer*
 MojoGpuMemoryBufferManager::GpuMemoryBufferFromClientBuffer(
     ClientBuffer buffer) {
   return gpu::GpuMemoryBufferImpl::FromClientBuffer(buffer);
 }
 
 void MojoGpuMemoryBufferManager::SetDestructionSyncToken(
     gfx::GpuMemoryBuffer* buffer,
     const gpu::SyncToken& sync_token) {
   static_cast<gpu::GpuMemoryBufferImpl*>(buffer)->set_destruction_sync_token(
       sync_token);
 }
 
 }  // namespace ui